Precision Rosenbluth Measurement of the Proton Elastic Electromagnetic Form Factors and Their Ratio at Q^2 = 2.64, 3.20, and 4.10 GeV^2

Due to the inconsistency in the results of the GEp/Gmp ratio of the proton, as extracted from the Rosenbluth and recoil polarization techniques, high precision measurements of the e-p elastic scattering cross sections were made at Q^2 = 2.64, 3.20, and 4.10 GeV^2. Protons were detected, in contrast to previous measurements where the scattered electrons were detected, which dramatically decreased epsilon-dependent systematic uncertainties and corrections. A single spectrometer measured the scattered protons of interest while simultaneous measurements at Q^2 = 0.5 GeV^2 were carried out using another spectrometer which served as a luminosity monitor in order to remove any uncertainties due to beam charge and target density fluctuations. The absolute uncertainty in the measured cross sections is \approx 3% for both spectrometers and with relative uncertainties, random and slope, below 1% for the higher Q^2 protons, and below 1% random and 6% slope for the monitor spectrometer. The extracted electric and magnetic form factors were determined to 4%-7% for GEp and 1.5% for GMp. The ratio GEp/Gmp was determined to 4%-7% and showed mu_p GEp/GMp \approx 1.0. The results of this work are in agreement with the previous Rosenbluth data and inconsistent with high-Q^2 recoil polarization results, implying a systematic difference between the two techniques.Comment: Ph.D. Thesis, Northwestern University, Advisor: Ralph E. Sege

Evaluation of human umbilical cord blood as a source of embryonic stem cells

Human umbilical cord blood (HUCB) has been poorly characterised as a source of embryonic stem cells (ESCs). The aim of this study, therefore, was to evaluate HUCB as source of mesenchymal stem cells (MSCs) with embryonic characteristics. HUCB was collected from consenting women undergoing elective caesarean sections. HUCB was meticulously explanted into MesenCult media and incubated. Qualitative and quantitative immunophenotyping of cells was achieved using fluorescein isothiocyanate (FITC) labelled antibodies (CD34, CD45, CD29, CD44, CD73 and CD105) phenotypic markers. Immunocytochemistry was carried out for the human ESC markers CD9, stage-specific embryonic antigen-1 and 4 (SSEA-1 and SSEA-4), E-cadherin, Podocalyxin (PODXL), sex-determining region Y-box 2 (SOX2), NANOG and Octamer (OCT3/4). MSCs were cultured to induce differentiation into adipogenic, osteogenic, chondrogenic and neurogenic cells. Immunocytochemistry was used to identify fatty acid binding protein-4 (FABP-4), osteocalcin, aggrecan, SOX2 and oligodendrocyte-4 (Olig-4) markers. The cells were strongly positive for the MSC markers CD29, CD44, CD73 and CD105; these cells also expressed the ESC markers CD9, SSEA-1 and SSEA-4, E-cadherin, PODXL, SOX2, NANOG and OCT3/4. Additionally, the MSCs expressed the adipogenic FABP-4, osteogenic osteocalcin, chondrogenic aggrecan and neural Olig-4 and SOX2 markers after differentiation. Therefore, HUCB is a rich source for MSCs with embryonic characteristics

Experimental and Analytical Characterization of Regenerated/nano Cellulose Composites

Fiber-reinforced composite materials are increasingly used for structural and engineering purposes. In particular, composites reinforced with natural fiber systems are becoming more and more popular due to their biodegradability and abundance; added to that other properties such as transparency, dimensional stability and good mechanical behavior. However, major issues remain to properly understand their behavior and enable their widespread use. In this thesis, the mechanical behavior of cellulose fiber/epoxy composites is investigated. The natural fiber systems studied fall into three categories: unidirectional regenerated cellulose fibers, triaxially braided quasi-isotropic regenerated cellulose fibers and micro-fibrillated cellulose in the form of nanocellulose scaffolds. Different methods of fabrication including wet layup, resin infusion, hot pressing and combinations of the three processes were investigated. Mechanical testing of tension coupons or three-point bending was performed to assess the mechanical behavior. When permitted, mechanical testing was accompanied by other validation techniques to help understand the mechanical behavior including digital image correlation (DIC) and acoustic emission. The effect of temperature and loading frequency on the mechanical behavior was also investigated by performing short beam testing using Dynamic Mechanical Analysis (DMA). Environmental effects, mainly the effect of moisture on the behavior of the fibers and the composites was also investigated. Additionally, the effect of the level of cure of the resin was found to have a detrimental effect on the mechanical behavior of the composites and was studied using DMA and Digital Scanning Calorimetry (DSC). Finally, the experimental results were extended and validated using numerical solutions and finite element simulations. Results show that thermal and mechanical properties are highly sensitive to the different factors being investigated; mainly humidity, temperature, manufacturing procedure and parameters, fiber content, as well as the level of curing of the epoxy

Experimental Validation of Shared Inverter Topology to Drive Multi AC-Loads

Many reduced-switch-count (RSC) inverter topologies have been proposed in the literature. As the number of switches required to produce a set of voltages in RSC inverters are less than that in conventional inverter, as a result utilizing RSC inverters in a certain system reduces its size and cost. In this paper, a novel RSC shared inverter topology consisting of fifteen switches and capable of driving four three-phase AC-loads independently is proposed and experimentally verified. A carrier-based pulse width modulation (PWM) technique that employs the zero-sequence-signal injection principle is developed to drive the proposed inverter along with adequate DC voltage bus utilization between the shared loads for common frequency (CF) as well as different frequency (DF) modes. The structure and the principle of operation of the proposed inverter are introduced and intensively verified using simulation and field-programmable-gate-array (FPGA)-in-the-loop simulation under linear and nonlinear loads. Then, Inverter prototype was built and the proposed inverter has been verified experimentally. The experimental results verify the applicability of the proposed inverter and the employed PWM

Reaching Out to Underserved High School Students: An Experiential Approach to Higher Education

Research indicates that underserved students are at a distinct disadvantage when it comes to entering and succeeding at college. However, with sufficient support, they can turn those disadvantages around. To address the persistent challenges of the underserved college-bound students, institutions of higher education created special pre-college outreach initiatives. This study provides finding regarding how an outreach program can apply experiential learning approach to motivate students through an experiential summer pre-business program that targets specifically targeted underserved high school juniors from various school districts in Southern California. This study also presents eleven years’ outcome assessment of this private university program. Using information from a survey and a lexical analysis of a sample of 574 students over 11-year period, this study finds that the experiential college outreach program increased underserved students’ drive for attending college and may be one promising practice to help close the gap in accessibility to higher education. The results illustrate the value of outreach programs provided by an institution of higher education to support underserved students through the fusion of business education and experiential learning

Flow injection analysis for the photometric determination of promethazine-HCl in pure and pharmaceutical preparation via oxidation by persulphate using Ayah 3SX3-3D solar micro photometer

The first flow injection spectrophotometric method is characterized by its speed and sensitivity which have been developed for the determination of promethazine-HCl in pure and pharmaceutical preparation. It is based on the in situ detection of colored cationic radicals formed via oxidation of the drug with sodium persulphate to pinkish-red species and the same species was determined by using homemade Ayah 3SX3-3D solar flow injection photometer. Optimum conditions were obtained by using the high intensive green light emitted diode as a source. Linear dynamic range for the absorbance versus promethazine-HCl concentration was 0-7 mmol.L-1, with the correlation coefficient (r) was 0.9904 while the percentage linearity (r2%) was 98.09%. the L.O.Q was 3.97 µg/sample, while L.O.D (S/N=3) = 0.2407µg/sample (5 µmol.L-1) from the stepwise dilution for the minimum concentration of lowest concentration in the linear dynamic range of the calibration graph. The R.S.D% at 2 mmol.L-1 promethazine-HCl is less than 1% (eight replicates) using 150 µL sample volume. Throughput 30 sample.hr-1. The method was applied successfully for the determination of promethazine-HCl in pharmaceutical preparation. By using paired t-test it was shown that there was no significant difference between the proposed method and official method and on that basis the new method can be accepted as an alternative analytical method

Hydrogen Bonds Effects on the Electrical Properties of Pectin/Pva Graphene Nanocomposites

Electrical properties were studied for Pectin/PVA graphene composites films and the effect of aqueous interaction on their properties. The conductivity and the dielectric constant of this composite are important because Polysaccharide like pectin is increasingly being used in biomedical applications and as nanoparticles coating materials. The Dielectric and conductivity of composite films were compared in dry and wet condition the differences in the results were attributed to the water molecules and the hydrogen bond which connect the three composite compounds (Pectin, PVA and Graphene) together. These connections were allowed the hydrogen and hydroxyl group’s migrations in the composite super molecules. On the other hand, graphene was prepared and with different techniques like Ft-IR, XRD, SEM and AFM characterized. Keywords: Hydrogen Bonds, nanocomposite , dielectric constant , Pectin/PVA graphene nanocomposit

Seismic Evaluation of I-24 Bridges and Embankments in Western Kentucky–Summary Report

I-24 is considered as one of the high priority and emergency routes in the region. Hence, it is essential that I-24 remains functional and operational after an earthquake event. The objective of this study is to perform seismic evaluation and risk assessment of bridges and embankments along I-24 in western Kentucky. The assessment assists identifying and prioritizing bridges that are susceptible to failure. The study aims at evaluating the seismic risk for 127 bridges, of which 82 bridges lies on I-24 and 45 bridges cross over I-24. This report is the first (1st) in a series of seven reports for Project SRP 206: “Seismic Evaluation of I-24 Bridges”. The seven reports represent a comprehensive study evaluating the seismic vulnerability of bridges and embankments along I-24 in western Kentucky. This report is intended to provide a summary of the results of the comprehensive study. Basic ranking results and/or deficiencies of the seismic performance of the 127 bridges are documented, and retrofit recommendations, if any, are presented in this report. However, all details and records for Project SRP 206, “Seismic Evaluation of I-24 Bridges”, are presented in the accompanied six reports